Search Results (45)

Objective: This study on children in low-income families explored whether their mental health problems are attributable to distress from five socioeconomic disadvantage factors playing roles in the multiple disadvantage model. These factors are social disorganization, social structural factors, social relationships, health/mental health, and access to care factors. Methods: The present study employed data extracted from the 2021 National Survey of Children’s Health, describing 7540 low-income children. Weighted logistic regression was conducted (with robust standard errors). Results: It showed that such children were more likely to have mental health problems when seven variables were present. The variables were argumentative children, parents’ difficulty with parenting, children’s difficult peer relations, children being bullied, families’ problematic substance use, families’ use of public health insurance, and families’ difficulty accessing mental health services. In turn, children were less likely to have mental health problems in the presence of six variables: a rundown neighborhood, an unsafe neighborhood, children’s Hispanic ethnicity, children’s Asian ethnicity, children’s general good health, and parents’ good mental health. The present study’s findings support the multiple disadvantage model. Conclusions: That is, the five types of factors key to the model (social disorganization, social structural, social relationships, health/mental health, and access to care) were observed to be related to low-income children’s mental health problems. These findings’ three main implications for practice are that it is crucial to (a) ensure children receive mental health services they need; (b) facilitate effective parent–child communication; and (c) provide low-income families with psychoeducation. Their main implications for policy involve two domains. Improving physical environments and safety in poor neighborhoods is necessary, as is enforcing schools’ anti-bullying rules and using schools to foster students’ assertiveness. Full article

Safe and adequate water supply, sanitation, and hygiene (WASH) in schools are prerequisites within the right to basic education. WASH facilities across schools in developing nations, particularly in Africa, are unsatisfactory and expose children to risks of disease and infection. This study aims to gather insights into the WASH status of secondary schools in Ibadan, Nigeria, to develop a sustainable water management framework for schools. A concurrent mixed-method design (questionnaires and interviews) was adopted to benchmark water management in schools and inform the design of a framework. Results reveal a wealth of issues and concerns that include infrastructure challenges accessing reliable and safe water supplies, rundown and unhygienic toilet/urinal facilities, and dilapidated sinks/taps, plus resource challenges, such as an absence of tissue paper and soap. These issues are exposing schoolchildren to unnecessary health risks, further supported by reported illnesses and reduced school attendance. Based on these findings, and guided by the UN SDG#6 targets, a water improvement framework has been created and validated by school officials. The framework identifies both short-term and long-term guidance/actions to improve water management in schools across Sub-Saharan Africa. These form crucial steps toward better WASH, building healthier communities and enhancing educational environments and outcomes for schoolchildren. Full article

The GABA_A receptors, through a short-term interaction with a mediator, induce hyperpolarization of the membrane potential (V_m) via the passive influx of chloride ions (Cl⁻) into neurons. The massive (or intense) activation of the GABA_ARs by the agonist could potentially lead to depolarization/excitation of the V_m. Although the ionic mechanisms of GABA_A-mediated depolarization remain incompletely understood, a combination of the outward chloride current and the inward bicarbonate current and the resulting pH shift are the main reasons for this event. The GABA_A responses are determined by the ionic gradients—neuronal pH/bicarbonate homeostasis is maintained by carbonic anhydrase and electroneutral/electrogenic bicarbonate transporters and the chloride level is maintained by secondary active cation–chloride cotransporters. Massive activation can also induce the rundown effect of the receptor function. This rundown effect partly involves phosphorylation, Ca²⁺ and the processes of receptor desensitization. In addition, by various methods (including fluorescence and optical genetic methods), it has been shown that massive activation of GABA_ARs during pathophysiological activity is also associated with an increase in [Cl⁻]_i and a decline in the pH and ATP levels in neurons. Although the relationship between the neuronal changes induced by massive activation of GABAergic signaling and the risk of developing neurodegenerative disease has been extensively studied, the molecular determinants of this process remain somewhat mysterious. The aim of this review is to summarize the data on the relationship between the massive activation of inhibitory signaling and the ionic changes in neurons. The potential role of receptor dysfunction during massive activation and the resulting ionic and metabolic disruption in neurons during the manifestation of network/seizure activity will be considered. Full article

Antibiotics have revolutionized medicine, with (fluoro)quinolones emerging as one of the most impactful classes of antibacterial agents. Since their introduction, four generations of (fluoro)quinolones have been developed, demonstrating a broad spectrum of activity, favourable pharmacokinetics, and clinical efficacy. However, the rise of multidrug-resistant pathogens has posed significant challenges to their continued effectiveness, particularly in healthcare settings. Among the main resistant species, Staphylococcus aureus, particularly methicillin-resistant strains (MRSA), Klebsiella pneumoniae, Enterococcus spp. (E. faecium and E. faecalis), Campylobacter spp., and Acinetobacter baumannii are the most important. This critical literature review provides an updated perspective on (fluoro)quinolones (old and new), encompassing their spectrum of activity, pharmacokinetics, mechanisms of resistance, and the role of antimicrobial stewardship in preserving their utility, to address the growing threat of resistance. Full article

Urban sprawl and brownfields are recognized as the main challenges for sustainable land use in post-industrial cities. Using a mixed methodology (GIS and interviews), this research aimed to examine the relationship between the redevelopment process of former Soviet military brownfields and urban sprawl in Hungary. Research findings highlighted the overall importance of the regeneration of military brownfields in urban development; however, not all the assessed projects appeared to be beneficial to densification objectives. We could identify two groups of brownfields lying within the boundaries of the compact city and outside the boundaries. The regeneration of military brownfields embedded in the built-up areas of cities can contribute to densification objectives and attract new functions and residents to abandoned areas. They can also support wider regeneration strategies of local governments, especially in run-down neighborhoods. However, a large number of military brownfields are located on the peripheries of metropolitan areas. The regeneration of such sites, as demonstrated by the case studies, can play a catalyst role in urban sprawl. Therefore, it is important to emphasize that local municipalities should make a careful strategic selection of military brownfield sites for redevelopment based upon their characteristics and location, as supported by the typology presented in this study, together with locally perceived socio-economic and risk factors. Full article

This study investigates the dynamic behavior of induction motors (IMs) by developing and validating four distinct mathematical models designed for transient and starting regimes. These models, expressed in α,β and d,q coordinate systems, analyze rotational frequency, electromagnetic torque, and current profiles with varying levels of complexity, including current-based, flux linkage-based, and rotor winding electromagnetic time constant approaches. Implemented in Fortran, the models address the limitations of predefined tools like MATLAB/Simulink, offering enhanced precision, flexibility, and suitability for non-standard scenarios. Validation against experimental data from a 3 kW induction motor confirms the models’ accuracy, with consistent results across approaches. Notably, the flux linkage models excel in capturing intricate transient phenomena, while current-based models simplify integration with power system studies. These findings provide a robust framework for analyzing IM performance under diverse conditions such as voltage unbalance and rundown scenarios, enabling the optimization of motor operations in energy-intensive industries. Full article

Overtopping phenomena and consequent floods cause significant damage to coastal communities. Morphological changes in front of structures during storms can influence their functionality, affecting their stability and leading to failures, impacting the population that are depending on those coastal interventions for their protection. The effect of climate changes, such as sea level rise and increase of the frequency and intensity of storms, can raise the number of overtopping events over defense structures, also increasing coastal morphological changes, challenging future managers, engineers and the scientific coastal communities. A review of morphological changes in front of coastal defense structures and in natural barriers due to overtopping, wave run-down and reflux was conducted. The objective of this review was to find and gather relevant information, sometimes dispersing, reflecting and grouping the concepts found in the literature. Additionally, the gaps in scientific research are addressed, focusing on topics that may be enhanced. Several keywords used in the research were presented, emphasizing the relationship between overtopping and models (physical and numerical), storms, defense structures and morphological changes, also related to wave run-down during storms. The results show that there is limited information available that is mainly related to morphological changes in front of coastal defense structures during storm events, showing an opportunity to develop knowledge. Full article

The development of restoration technology and meadows, improvement of run-down pastures, and productivity improvement of old crops of perennial grasses is an urgent problem in agriculture. The tillage traction force in seeder designing and manufacturing is an important indicator of energy efficiency. The objective of this work is to reduce traction force and ensure seeding depth uniformity by justifying the optimal chisel parameters of a grain–fertilizer–grass seeder for direct seeding in sod. The Box–Behnken method was applied to investigate the traction force dependence on the seeder velocity, seed embedding depth, chisel width, and mounting angle. The obtained optimal parameters of coulters were justified by the finite element method. Structural and technological parameters were checked using the smoothed-particle hydrodynamics method on the deformation and wear of the seeder working body. The revealed optimal coulter parameters were as follows: chisel width was 20–20.97 mm, chisel length was 145–148.9 mm, mounting angle was 75°–81.6°, and achieved minimum traction force was 720 N. These parameters ensure the quality of grass seed embedding in the sod. The theoretical data of traction force (8.27–8.39 kN) are in accordance with the experimental (8.28–8.63 kN) data under field conditions. These findings are efficient in agrotechnical and mechanical predictions regarding the occurrence of chisel residual stresses and the working lifetime of the part. Full article

This research aims to develop an efficient and accurate model for simulating tuned liquid dampers (TLDs) with sloped beds. The model, based on nonlinear shallow water equations, is enhanced by introducing new terms tailored to each specific case. It employs the central upwind method and Minmod limiter functions for flux and interface variable assessment, ensuring both high accuracy and reasonable computational cost. While acceleration, slope, and dissipation are treated as explicit sources, an implicit scheme is utilized for dispersion discretization to enhance the model’s stability, resulting in matrix equations. Time discretization uses the fourth-order Runge–Kutta scheme for precision. The performance of the model has been evaluated using several test cases including dam-breaks on flat and inclined beds and run-up and run-down simulations over parabolic beds, which are relevant to sloshing in tanks with sloped beds. It accurately predicts phenomena such as asymmetric sloshing waves, especially in sloped beds, where pronounced waves occur. Dispersion and dissipation terms are crucial for capturing these effects and maintaining stable wave patterns. An initial perturbation method assesses the tank’s natural period and numerical diffusion. Furthermore, the model integrates with a single-degree-of-freedom (SDOF) system to create a TLD model, demonstrating enhanced damping effects with sloped beds. Full article

Wind is a significant factor influencing the stability of breakwater armor stones. However, few existing studies have considered the effects of wind on these structures. In this study, two-dimensional laboratory experiments were conducted to examine the effect of wind on the stability of breakwater armor stones. The stability factor ($K_D$) of the armor stone, fluid velocity, runup, and rundown were observed under the action of waves and winds. A wind turbine was installed in front of the physical model of the breakwater to generate extreme wind conditions of 5.5 and 12 m/s. The results showed that $K_D$ decreased by 42.18% at 5.5 m/s and 57.82% at 12 m/s compared with that without wind. The maximum runup and rundown heights increased with wind velocity, following a Rayleigh distribution. The fluid velocity distribution conformed to a normal distribution, with the mean velocity directed offshore. Many studies have suggested that runup, rundown, and fluid velocity are the main factors affecting the stability of breakwater armor stones. The analysis revealed that wind affects these factors and lowers the stability coefficient. These wind-induced hydrodynamic changes suggest the need for a detailed hydrodynamic review of wind-wave conditions. Full article

The driving and resistance torques of some rotating machinery for industrial applications are nonstationary and affect system dynamics. Under such operating conditions, coupling between torsional and lateral vibrations may become significant for drive lines supported by hydrodynamic bearings in particular design configurations. Indeed, the occurrence of fluid–structure interactions causes a reduction in the stability threshold of the journal bearings. A hypothesis based on Hopf bifurcation theory (HBT), which justifies how the coupling phenomenon develops, is validated by means of overall experimental observations and a suitable numerical model. When the pulsating driving torque induces significant angular speed oscillation, the rotor-bearing system lateral operating response becomes more complex, and bearing instability onset is detected. Such observation proves the influence of bearings in converting torsional oscillations to lateral vibrations. Particularly, during run-up and run-down tests, localized hysteresis is observed in trends of fundamental order contents. The numerical model of the hydrodynamic bearings solves the Reynolds equation in unsteady conditions to quantify the lateral vibrations amplitude in the presence of both angular speed oscillation and dynamic perturbation. The proposed approach proves the onset of torsional–lateral vibration coupling due to hydrodynamic bearings, to a certain extent. The detected hysteresis phenomena can also be explained by the onset of journal bearing instability. Full article

Among the most prevalent neurological disorders, epilepsy affects about 1% of the population worldwide. We previously found, using human epileptic tissues, that GABAergic neurotransmission impairment is a key mechanism that drives the pathological phenomena that ultimately lead to generation and recurrence of seizures. Using both a “microtransplantation technique” and synaptosomes preparations from drug-resistant temporal lobe epilepsies (TLEs), we used the technique of two-electrode voltage clamp to record GABA-evoked currents, focusing selectively on the synaptic “fast inhibition” mediated by low-affinity GABA_A receptors. Here, we report that the use-dependent GABA current desensitization (i.e., GABA rundown, which is evoked by applying to the cells consecutive pulses of GABA, at high concentration), which is a distinguishing mark of TLE, is mainly dependent on a dysfunction that affects synaptic GABA_A receptors. In addition, using the same approaches, we recorded a depolarized GABA reversal potential in synaptosomes samples from the human epileptic subicula of TLE patients. These results, which confirm previous experiments using total membranes, suggest an altered chloride homeostasis in the synaptic area. Finally, the lack of a Zn²⁺ block of GABA-evoked currents using the synaptosomes supports the enrichment of “synaptic fast inhibitory” GABA_A receptors in this preparation. Altogether, our findings suggest a pathophysiological role of low-affinity GABA_A receptors at the synapse, especially during the fast and repetitive GABA release underlying recurrent seizures. Full article

Spinal manipulation (SM) is a common manual therapy technique; however, there is limited knowledge regarding the coordination of hand and foot forces during SM. This study investigated the biomechanics of force transmission and generation in the hands and feet of a single therapist who performed pelvic SM on 45 healthy subjects. Two force plates were used to measure the ground reaction forces (GRF) from the feet, and one controller was used to measure the contact hand forces (CHF). The results showed that foot force preceded hand force and that the foot and hand exhibited opposing patterns of force variation. The CHF peak was positively correlated with the CH preload maximum and minimum forces and negatively correlated with the GRF run-down. These findings suggested that the therapist used a coordinated strategy of avoiding weight support with the feet and supporting the weight with the hands to amplify the thrust force. This study provides new insights into the biomechanics of SM and has implications for teaching, motor learning, and safety. Full article

This paper considers the equipment and power supply schemes for urban water supply, heat supply and sewerage pumping stations. Mathematical calculations of the impact of the static and full centrifugal pumps pressure ratio on the dynamic stability of synchronous electric motors were carried out. An analysis of the influence of pump parameters and engine load on the run-down parameters and drive stability during power shutdowns was carried out. It has been theoretically proven and practically confirmed that ensuring the stability of pumping station drives and the reduction in enterprise losses during various short-term disruptions in power supply networks can be provided by means of a high-speed backup source with a response time of less than 9 ms, dynamic voltage dip compensators with a response time of less than 3 ms and uninterruptible power supply sources. Full article

Cholangiocarcinomas (CCAs) constitute a heterogeneous group of highly malignant epithelial tumors arising from the biliary tree. This cluster of malignant tumors includes three distinct entities, the intrahepatic, perihilar, and distal CCAs, which are characterized by different epidemiological and molecular backgrounds, as well as prognosis and therapeutic approaches. The higher incidence of CCA over the last decades, the late diagnostic time that contributes to a high mortality and poor prognosis, as well as its chemoresistance, intensified the efforts of the scientific community for the development of novel diagnostic tools and therapeutic approaches. Extracellular vesicles (EVs) comprise highly heterogenic, multi-sized, membrane-enclosed nanostructures that are secreted by a large variety of cells via different routes of biogenesis. Their role in intercellular communication via their cargo that potentially contributes to disease development and progression, as well as their prospect as diagnostic biomarkers and therapeutic tools, has become the focus of interest of several current studies for several diseases, including CCA. The aim of this review is to give a rundown of the current knowledge regarding the emerging role of EVs in cholangiocarcinogenesis and their future perspectives as diagnostic and therapeutic tools. Full article